The invention relates to a process for operating an exhaust gas burner, particularly in the regeneration of soot filters or the like, especially with regard to the turning on of the exhaust gas burner to start the process. Further, the invention also relates to a device for operating an exhaust gas burner that has a turning-on control device.
In regeneration units, particularly of soot filters in diesel internal combustion engines using an exhaust gas burner, a problem exists in that the oxygen content of the exhaust gases is subject to fluctuations which depend chiefly on the instantaneous engine performance characteristics. However, when the oxygen content of the exhaust gas is low, starting, that is igniting, of an exhaust gas burner which is operated with the exhaust gases as the combustion air source causes extremely great difficulties. In many cases, the ignition spark energy delivered by an ignition device, up to now, has been insufficient. Thus, the process of regenerating a downstream soot filter unit, for example, cannot be started satisfactorily. Furthermore, attempts to commence burner ignition under unsatisfactory conditions is not only futile, but is also destructive from a wear standpoint as well as from the effects of excess fuel accumulations resulting from repeated unsuccessful startup attempts. Examples of soot filtering units that utilize an exhaust gas burner for regeneration purposes can be found in commonly owned U.S. patent application Ser. Nos. 196,557 and 196,558, filed May 20, 1988 by the present applicant.